CZ296708B6 - Prosthesis - Google Patents

Abstract

The present invention relates to a prosthesis comprising "Z" stents (7, 8) sutured to a graft comprising a biocompatible material tube (5) such as Dacron. The "Z" stents are attached to the inside surface of the Dacron tube (5) and there is at least one fenestration (10) in the Dacron tube (5) corresponding to an intersecting artery opening. A further "Z" stent (1) extends proximally and they may have caudally facing barbs (2). Each fenestration (10) includes one or more radiopaque markers (11) defining a periphery of the fenestration (10). A release mechanism for said prosthesis includes at least one trigger wire (15) wherein a portion (16) of the Dacron tube (5) made of biologically compatible material is folded in longitudinal direction along with said at least one trigger wire (15) extending lengthwise through the tube (5) into a fold to retain the prosthesis in a partially compressed state during deployment.

Description

Prosthesis

Technical field

The present invention relates to a prosthesis found to be of use generally in the field of treatment of aortic disease.

The present invention is particularly directed to endoluminal aortic stents and methods of developing such stents that allow for accurate placement of the covered stent in the aorta, deployment and placement exactly above the renal arteries in the treatment of infrarenal aortic aneurismatic disease.

BACKGROUND OF THE INVENTION

To date, aortic disease is often treated with surgical techniques, including the use of stents and grafts. For example, it is well known in the art to include stents within a stenotic portion of an artery made of either stainless steel or other balloon-expandable materials to strengthen the walls of a stepotic or occluded artery. Further, the use of a graft to repair highly damaged parts, such as the aorta or other arteries, which maintain blood flow and reduce the risk of disease spread or rupture of the arteries is well known to date. The grafts, hollow tubes containing such materials as dacron, are normally inserted into the walls of the damaged artery and can be sewn into position or expanded using a stent balloon catheter.

A more serious problem arises when it is necessary to use a graft in or around the intersection of the main artery (eg, aorta) with the intersection arteries (eg, renal artery, throat or short-lined artery). While the graft is clearly required to enhance and ensure blood flow, for example by the aorta, the use of the graft effectively closes or blocks blood flow to the kidneys or brain circulation. Therefore, it is often impossible or impractical to use the graft to treat aortic disease or around the intersection of the aorta and other arteries. Instead, the surgeon must attempt to repair the weakened walls of such an artery using other surgical techniques that have a high failure rate and limited success. For example, although several centers around the world routinely develop endoluminal grafts for the treatment of infrarenal aortic aneurism, up to 30% of abdominal aortic aneurisms are unsuitable for this method of treatment due to insufficient aneurism-free infrarenal artery length to firmly graft the graft or stent.

CZ 284 329 describes a graft body shaped into a pouch with openings in the bottom region of the pouch. Neither tube walls nor fenestration in the tube wall are described.

WO 97/45073 discloses a set of balloon expandable stents that are constructed in such a way that no other set of stents can be attached to them. There is no tube wall, and there can be no fenestration in such a wall.

The present invention solves the problem of prior art by using the suprarenal artery to provide adequate anchorage for the aortic graft, while at the same time employing an extremely accurate location of the perforated covered stent that corresponds to the exact original sites of the intersection arteries.

SUMMARY OF THE INVENTION

The present invention provides a prosthesis comprising a tube of biocompatible material, at least two Z stents sewn into a tube of biocompatible material, and at least one fenestration in the tube coincident with the aperture of the intersection artery and wherein at least two Z stents are positioned proximally and distally from the at least one fenestration, and each of the stents is located entirely within the tube.

- 1 GB 296708 B6

According to a preferred embodiment, the prosthesis further comprises an additional Z stent mounted in the tube and extending proximally from the tube. Particularly preferred is a prosthesis in which the other Z stent has a caudal trim on the teeth.

Another preferred embodiment of the prosthesis is that at least two fenestrations are provided in the tube in accordance with the respective intersectional arteries.

Yet another preferred embodiment of the prosthesis is that the fenestration comprises at least one radiopaque mark defining the edge of the fenestration.

Another preferred embodiment is that the most distal of the Z stents comprises a loop extending distally from the tube.

A preferred embodiment of the prosthesis also comprises a release mechanism comprising at least one trigger wire, wherein a portion of the tube of biocompatible material is folded longitudinally with at least one trigger wire extending longitudinally of the tube in translation to keep the prosthesis partially compressed.

The present invention is described in more detail below.

The present invention generally relates to a perforated endoluminal aortic stent that is a single component device comprising two or more Z stents made of stainless steel or nitholium, which may have a caudal rack rim stitched to a different tube length of a biocompatible material in which the Z stents are attached to the inner surface. the tubing of the biocompatible material and, depending on the geometry of the intersection arteries to be covered, adapted to the fenestrations precisely positioned in the tubing of the biocompatible material to the corresponding apertures of the intersection artery.

Thus, in one embodiment, the invention consists of a prosthesis comprising two or more Z stents sewn into a graft containing a tube of biocompatible material, wherein two or more Z stents are attached to the inner surface of the tube of biocompatible material and at least one fenestration from the tube of a biocompatible material corresponding to the aperture of the intersection artery.

Preferably, they are more than whether the Z stents are connected to a tube of biocompatible material.

The other Z stent may be mounted in a tube of biocompatible material and expanded proximally from the tube of biocompatible material.

At least one of the Z stents may have caudal hemming of the barbs to help accurately retain the prosthesis when fully inserted.

The proximally expanded Z stent may be a stent having a caudal trim on the teeth.

The tube of biocompatible material may be made, for example, of dacron.

There may be two or more fenestrations depending on the number of intersection arteries.

The or each fenestration may include one or more radiopactual markers defining the edge of the fenestration.

The distal majority of the Z stents may include a loop extending the distal graft.

- 2 GB 296708 B6

The prosthesis may further comprise a release mechanism comprising one or more trigger wires wherein a portion of the biocompatible material tube is folded longitudinally with the one or more trigger wires respectively threaded longitudinally through the biocompatible material tube and folded to keep the prosthesis partially compressed.

At least one of the Z stents may comprise one or more truncation loops to allow placement of the desired fenestrations.

Accurate placement of aortic clamps can be achieved by computerized axial tomograms (CT) and angiography, and the invention is adapted to each patient in relation to sites corresponding to CT. Fenestrations are labeled with radiopaque beads to allow them to be placed under X-ray control prior to deployment.

In an alternative embodiment, the invention may be applied in a method of treating an arterial disease at the intersection of two arteries including the steps of:

X-ray arteries are treated as accurately determining the position of the intersection of the arteries, adapting one or more fenestrations to the prosthesis containing a selected tube length of biocompatible material, attaching radio-opaque marks around this or each fenestration, placing two or more Z stents in tubes of biocompatible material, bends on Z stents are shortened if necessary in such a way that they do not overlap the fenestrations, manually joins the top of the Z stents, covers the top of the Z stents with the top cap, and holds the Z stents in place in the top with a trigger wire, the trigger wire or other trigger wire is sutured through the longitudinal composition in a tube of biocompatible material to narrow the cross-section of said prosthesis, thereby providing a matched perforated cover graft for insertion into the artery to be treated.

The method may further comprise a stitching step, and further Z stents round off the top of the step of said biocompatible material tube, such that an additional Z stent extends proximally from the biocompatible material tube.

More than two of said Z stents may be attached to a tube of biocompatible material by two or more fenestrations, depending on the number of arterial intersections.

The graft insertion process may include the steps of: pushing the graft into position and locating it comfortably around said upper cap of the prosthesis, stents and cap, inserting the prosthesis through the femoral artery in the groin of the prosthesis into a delivery device that includes the upper cap, housing , a cap and guide wires, retracting the sheath to expose the graft in a semi-advanced position, positioning the prosthesis, partially retracting the sheath and cap to allow insertion of angiographic catheters and guide wires, insertion of angiographic catheters and guide wires by a contralateral groin treated to provide the ability to maneuver, precisely position the graft by positioning right and left with angiographic catheters and guide wires through fenestration into the intersection of the arteries, releasing the trigger wire to provide full graft deployment, angiogra contraction and discharging the capsule and cap through the stent and delivering to the top cap and fully retracting the delivery device, wherein said full deployment of the stents detects blood flow at the intersection of the arteries to be treated.

The method by which the prosthesis of the present invention is to be maneuvered in place prior to full deployment is performed via the right and left angiographic catheters and guide fibers.

Radiopactic labels may be gold or any biocompatible material that allows the label to be visualized under X-rays or other methods.

- 3 GB 296708 B6

The invention is generally described above, but for a better understanding of the invention, preferred embodiments will now be illustrated by the accompanying drawings.

Overview of drawings in drawings

One embodiment of the present invention will now be described with reference to the drawings in which:

Giant. 1 is an exterior view of one embodiment of the present invention illustrating an upper portion of Z stents, a tube of biocompatible material with fenestrations and small radiopactic beads, and a metal loop based tube of biocompatible material;

Giant. 2 is an internal view of an embodiment of the present invention illustrating internal Z stents and fenestrations for intersection of arteries;

Giant. 3 is an external perspective view of an embodiment of the present invention illustrating how a tube material of biocompatible material can be folded back and held in place with the trigger wire wired. Of the stents attached to the inner surface of the biocompatible tube material, they are incomplete to allow later a section of the biocompatible tube material to be folded and held with a trigger wire passed through the material;

Giant. 4 is a cross-sectional view of an embodiment of the present invention prior to release of the trigger wire;

Giant. 5 is a cross-sectional view of an embodiment of the present invention after releasing the trigger wire. The trigger wire is retracted and the composite biocompatible material is undeveloped, allowing the stent to extend to its full width, while keeping it against the aortic wall with radial force;

FIG. 6 is a view of the aorta and renal artery with a prosthesis according to this embodiment of the present invention by a delivery device. The upper portions of the stents of the present invention are manually pulled together and covered with the top lid, while the lower portion of the present invention is seated comfortably above the closure and in the housing, all threaded through a guide wire that installs in the correct position of the present invention;

Giant. 7 is a view of the prosthesis of this embodiment of the present invention after being released from the capsule in a semi-deployed position against the renal arteries, i.e. prior to release of the trigger wire;

Giant. 8 is a view of a prosthesis from this embodiment of the present invention in a semi-deployed position wherein the fenestrations of the present invention are cannulated with a guide wire from a contralateral flank through which two angiographic catheters are routed to secure the stents firmly in the correct positions before fully unfolding; a trigger wire;

Giant. 9 is a view of the prosthesis from this embodiment of the present invention in its full deployment, i.e. upon release of the trigger wire with angiographic catheters and the top cap still in place;

Giant. 10 is a view of a prosthesis according to this embodiment of the present invention in rigid deployment with angiographic catheters and their guide wires contracted, and a delivery device closure that is extruded to remove the top cap in preparation for retraction of the delivery device; and

Giant. 11 is a view of a prosthesis from this embodiment of the present invention in full deployment providing flow to the renal arteries through the capsule, cap and retracted upper cap.

- 4 GB 296708 B6

DETAILED DESCRIPTION OF THE INVENTION

Description of a preferred embodiment of the invention

The present invention relates generally to the field of treatment of aortic diseases, in particular to the use of endoluminal aortic stents that permit the accurate placement of a perforated opaque stent in an artery. In particular, this allows the stent to be deployed and positioned exactly above the renal arteries in the treatment of infrarenal aortic aneurismatic disease.

The attached figures show the basic steps used in the method contemplated, as well as illustrating features of one embodiment of the present invention.

Giant. 1 and 2 show an external view of one embodiment of the present invention. The proximal stainless steel or nitinol stent 1 with caudally lined barb 2 is sewn with the upper ring 4 of the tube 5 of biocompatible material. The proximal Z stent 1 extends proximally from a tube 5 of biocompatible material. Two other Z stents 7, 8 of stainless steel or nitinol are pressed into a tube 5 of biocompatible material. The stents 7, 8 are sewn at certain distances into the biocompatible material tube 5, but a portion of the suture of the biocompatible material tube 5 is omitted to allow longitudinal folding of the biocompatible material tube as will be mentioned later. The perforations 10 are provided in a tube 5 of biocompatible material to provide a slit in the tube that will be attached to the renal or other arteries in use. The perforations 10 are sized and positioned for renal arteries according to computed tomography and angiography, and their outer edges are labeled with small gold radiopaque beads 11, which help to identify perforations by X-rays. The long loop 12 is in one of the crowns of the stent 8 which extends the distal tubes 5 of biocompatible material and which grips the front of the stent in the delivery device, as will be described later.

As can be seen in particular in FIG. 2, which shows an internal view of the prosthesis, there is a shortened loop 13 of one of the crowns of the upper portion of the inner Z stent 7 which allows the perforations for the renal arteries to be positioned.

Giant. 3 is a perspective view of a prosthesis where the proximal crowns 14 of the stent 1 are together manually contracted to facilitate insertion into the proximal capsule (not shown). The trigger wire 17 is used to hold the crowns in the capsule. The same trigger wire or other trigger wire 15 is also used to hold the longitudinal fold in the tube 5 of biocompatible material, thereby narrowing the diameter and allowing lintel 16 from the excess material to the prosthesis side. The trigger wire 17 also extends through a loop 12 to assist in maintaining the distal end of the prosthesis after the sheath is struck, as will be described later. This allows the prosthesis to rotate in the artery to specify the position before final release. The trigger wire 15 is inserted through a surface of dacron or other discontinuous material to form a series of stitches to form the scar lintel material 16, which is more clearly shown in Fig. 4.

Giant. 4 shows a cross-sectional view of the prosthesis before releasing the trigger wire 15 from the lintel 16. The scar lintel 16 held in place by suturing the trigger wire 15 provides a diameter that is narrower than the aortic diameter, allowing the prosthesis to be maneuvered both up and down and rotate 360 °, releasing the present invention from the capsule, and after cathetering, as will be discussed in connection with Fig. 8, to ensure accurate placement of the perforations relative to the renal arteries.

Giant. 5 shows a cross-sectional view of the prosthesis after releasing the trigger wire, that is, in full deployment.

- 5 GB 296708 B6

Giant. 6 is a view of the aorta 30, the kidney arteries 32 and 34 extending to the kidneys 35 and the femoral arteries 36 and 38 and the delivery device that introduces the prosthesis 18 of the present invention into the aorta 30 by cutting the groin into one of the femoral arteries 36.

The delivery device generally designated 20 is inserted over the plastic coated metal guide wire 22 and includes a stainless steel proximal cap 24 mounted on a flexible steel tube 23. The proximal cap 24 covers the top of the proximal Z stent and the capsule 26 covers the prosthesis including a tube 5 of biocompatible material and the remainder of the stents Z extends over a portion of the proximal cap 24 during insertion. The housing 26 is provided with a plastic closure 28 that is long enough to protrude from the femoral artery and groin section to allow manual movement. The plastic closure 28 is slidably connected to a flexible steel tube 23. The closure 28 is mounted below the sleeve and holds the prosthesis in position both during insertion and later when the sleeve is pulled back over the closure as shown in Fig. 7 thereby exposing the perforated stent in the semi-deployed position shown in Fig. 3.

In Figure 7, the sleeve 26 is pulled into the closure 28 while leaving the closure 28 and the proximal capsule 24 at the point of preventing relative movement between the flexible steel tube 23 and the closure 28. The prosthesis 18 is then free to rotate by moving the flexible steel tube 23 and moving longitudinally. until perforations 10 and 11 are positioned correctly with respect to renal arteries 32 and 34.

Giant. 8 is a view of the aorta 30, the kidney arteries 32 and 34 extending to the kidneys 35 and the femoral arteries 36 and 38 and the delivery device 20 wherein the cap 28 and the sleeve 24 are retracted into one of the femoral arteries 36. This is accomplished by holding a flexible steel the tubes 23 immovably and by moving the sleeve 26 and the closure 28 relative to the sleeve. The trigger wire 15 remains in place. This allows space for insertion of guide wires 40 and 42 and angiographic catheters 44 and 46 that are inserted through the incision in the contralateral groin (not shown) and through the contralateral femoral artery 38 and positioned in the renal arteries, right and left angiographic catheter 44 and These angiographic catheters 44 and 46 are constructed with right and left bending of the necks to guide the wire from the aorta 30 to a suitable renal artery 32 and 34. The guide wires 40 and 42 and the angiographic catheters 44 and 46 are inserted into the renal arteries 32 and 34 to ensure safe and accurate placement of the prosthesis perforations 10 and 11 of this embodiment of the present invention.

Giant. 9 is a view according to the present invention of fully deploying the release wires 15 and 17 or a single trigger wire to perform the functions of both the guide wires with the guide wires 40 and 42, the angiographic catheters 44 and 46 and the delivery device 20 still in place. At this stage, the proximal Z stent 1 expands to the aortic wall 30 and the cog 2 engage the aortic wall to hold the prosthesis 18 in the correct position.

In Fig. 10, angiographic catheters 44 and 46 and guide wires 40 and 42 are drawn through the contralateral femoral artery 38 and cap 28 and the capsule 24 is formed to accommodate the proximal capsule 24 in preparation to remove the complete delivery device 20. This is achieved by holding a flexible steel the tube 23 immovably and by moving the closure 28 and the sleeve 24 relative to and towards the proximal capsule.

Giant. 11 is a view of the prosthesis 18 of the present invention fully developed, with the delivery device 20 retracted, allowing free blood flow through the aorta 30 and into the renal arteries 32 and 34 through perforations 10 and Π.

After the angiograph has been unfolded, the correct unfolding and positioning of the perforations should be confirmed.

The modifications that can be made, which may be advantageous are as follows:

More than two Z stents may be attached in a tube of biocompatible material. More than two Z stents can be used if stretching of the graft of the present invention is desired.

- 6 GB 296708 B6

The release mechanism may be inserted internally (a) later or (b) beforehand and later with one or two trigger wires.

There may be more than two perforations in the tube of biocompatible material if there are more than two intersection arteries.

In the description and claims below, unless the context requires otherwise, the words "include" and "include" and variations thereof, such as "comprising" or "comprising" shall be understood to include the content of the indicated whole or groups of units, but other units or groups of units are not excluded.

PATENT CLAIMS

Claims (7)

A prosthesis comprising a tube (5) of biocompatible material, at least two Z stents (7, 8) sewn into a tube (5) of biocompatible material, and at least one fenestration (10) in the tube (5) coincident with the aperture of the intersection artery, and wherein at least two Z stents (7, 8) are located proximally and distally from the at least one fenestration (10) and each Z stent (7, 8) is located entirely within the tube (5). The prosthesis of claim 1, further comprising a further stent (1) mounted in the tube (5) and extending proximally from the tube (5). Prosthesis according to claim 2, characterized in that the other Z stent (1) has a caudal trim on the teeth (2) thereon. Prosthesis according to claim 1, characterized in that at least two fenestrations (10) are provided in the tube (5) in accordance with the respective intersectional arteries. Prosthesis according to claim 1, characterized in that the fenestration (10) comprises at least one radiopaque mark (11) defining the edge of the fenestration (10). Prosthesis according to claim 1, characterized in that the most distal of the Z stents (8) comprises a loop (12) extending distally from the tube (5). The prosthesis of claim 1, further comprising a release mechanism comprising at least one trigger wire (15), wherein a portion (16) of the tubing (5) of biocompatible material is folded longitudinally with the at least one trigger wire (15) guided. longitudinally by a tube (5) in translation to keep the prosthesis partially compressed.